What is the blendcache_learning folder?
Smoke simulations, and – if "Disk Cache" is selected – also cloth and soft body simulations, will create a folder called blendcache_$file where $file is the name of your .blend file (fluid simulations will create cache_$file instead). 

Those folders contain the results of baking the physics. Deleting them clears the bake; to bring your bake around (to another computer) it's necessary to keep those folders as sub-folders of your project.